Even the file name might get lost or changed. a.txt /tmp/test/a.txtĨ5ec58226886f4f853212b2d21bb2fb72447813ac13a59e9376b2e0c02074839 -Ģ5c1c072481131e07c3fc20d16109472872233f658f4df3c4982fb195a048b96 -Īdding timestamps, owners and such to the equation would almost guarantee the hashes being different after the file was copied to another system, making the usefulness of the hash rather questionable. Obviously, including the file name has the disadvantage that even the very same file can be referenced to by different names and can hence have numerous distinct hashes: /tmp/test$. Another application could include metadata in the hash input along with the file contents, or include hashes that only cover part of the data. The script simply prepends the file names to the hashed data. Not the file name, not the permission bits, owner information, timestamps or other metadata.īut it doesn't have to be done like that. Now, you perhaps used the sha1sum, sha256sum and md5sum utilities, and indeed they only include the contents of the given file in the data to be hashed. So, the result you get depends entirely on what you choose to give as the input, and you didn't show that. SHA-1, SHA-256 and MD5 don't calculate hashes of files or file names, they calculate hashes of bit streams. Well, this is somewhat a false connection.

When I change a file's name this does not affect its checksum (I've tried SHA-1, SHA-256 and MD5).

File checksum